Spanner for electrified fencing



May 30, 1944. s. A. MOORE SPANNER FOR ELECTRIFIED FENCING Filed Aug. 3, 1942 Patented May 30, 1944 UNITED STATES PATENT OFFICE SPANNER FOR ELECTRIFIED FENCING Sidney A. Moore, Milwaukee, Wis., assignor to The Prime Manufacturing Company, Milwaukee, Wis., a corporation of Wisconsin Application August 3, 1942, Serial No. 453,380

8 Claims.

This invention relates to electrified fencing and. refers particularly to protective electrified fence installations of the type forming the subject matter of the copending application of Sidney A. Moore, Serial No. 453,379, filed August 3, 1942.

One of the purposes of such electrified fencing is to set off an alarm in the event of any tampering with the fence, and to this end the fence consists of wires strung as a barrier with adjacent wires from different circuits and insulated from each other and ground. As fully described in the aforesaid copending application, the fence circuits are connected with an alarm system in such a manner that a short circuit between adjacent wires, the grounding of any wire, or the cutting of any wire, sets off the alarm.

However, unless the posts or supports upon which the wires are strung are relatively close together and the wires are exceptionally taut and strong it might be possible to defeat the fence by holding adjacent wires far enough apart by means of some adequately insulated instrumentality, to enable a person to step through the fence without contacting any wire.

As indicated, this can be precluded by having the posts or supports sufliciently close together and the wires so taut and strong that they could not be flexed sufficiently to provide the necessary opening, or it could be precluded by having the wires closer together. All of these expedients, however, entail considerable additional expense which makes them generally not feasible.

It is, therefore, an object of the present invention to provide a novel manner of assuring the short circuiting of the fence circuits whenever the fence wires are abnormally flexed as a result of an effort to spread adjacent wires far enough apart to enable a person to step through the fence.

More specifically, it is an object of this invention to provide a fence spanner adapted to be mounted on an electrified fence between its supports and so attached to the fence that abnormal deflection or flexure of any wire thereof establishes an electrical connection between the circuits of the fence to set off an alarm.

Another object of this invention is to provide a spanner of the character described which is so designed and constructed that it may be made up in long lengths to be cut off into pieces of any required length.

Another object of this invention resides in the provision of a novel manner of applying the spanner to the fence.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims. The accompanying drawing illustrates one complete example of the physical embodimentof the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:

Figure l is a view diagrammatically illustrating a section of an electrified fence having the spanner of this invention applied thereto;

Figure 2 is a perspective view showing a por tion of the spanner and illustrating its attachment to the fence; I

Figure 3 is a perspective view illustrating the manner in which the attachment of the spanner to some of the fence wires is effected;

Figure 4 is a side view illustrating a section of the spanner prior to its application to the fence; and

Figure 5 is a perspective view illustrating the manner in which the spanner may be commercially handled.

Referring now particularly to the accompanying drawing, in which like numerals indicate like parts, the numeral 5 designates the posts or supports of an electrified fence upon which electrically charged wires 6 are mounted. The wires 6 are insulated from the posts or supports in the customary manner and are divided into two circuits A and B, with adjacent wires alternately from opposite circuits.

To guard against the possibility of spreading adjacent wires far enough, through use of some suitably insulated instrumentality, to permit a person to step through the fence, at least one spanner. indicated generally by the numeral 1,

mounted on the fence between each pair of ad-- .iacent posts or supports. The number of such spanners required between the posts or supports depends upon the distance between posts.

The spanner consists of a relatively stiff wire 8 long enough to span all of the fence wires when positioned vertically against the fence, and having a plurality of lengths of relatively flexible wire 9 electrically and mechanically secured thereto at spaced intervals.

One of these flexible Wires is wrapped about the upper strand of fence as at Ill to electrically and mechanically connect the top of the spanner with the upper strand of the fence. The upper strand of the fence being in circuit A, it follows that the spanner must be normally insulated from the wires of the circuit B and to this end the flexible lengths of wire 9 adjacent the strands of the circuit B are formed into loops H which encircle the adjacent fence wires (of circuit B) but are spaced therefrom.

The manner in which the flexible lengths of wire are formed into theseloops H is illustrated in Figure 3. As here shown, a split conical mandrel I2 is placed on the fence wire opposite the spanner and then the free end of the adjacent flexible wire 9 is wrapped about the mandrel and secured to the spanner wire a as at I3.

The remaining strands of the fence wire, all of which are in circuit A, are mechanically but not electrically connected to the spanner and to this end split insulators l4 having annular grooves for the reception of the flexible wires are placed over the fence wires and the flexible wires wrapped about them, as clearly shown in Figure 2,. the free ends of the flexible wires being secured to the spanner wire as at l5.

Thus, it will be seen that the spanner is held against swaying and that as long as the fence Wires remain taut and in their normal positions the circuits are not shorted. However, if any one wire of the fence is forcibly moved or flexed out of its normal position, relative movement takes place between at least one of the strands of circuit B and the loop ll encircling it, causing the same to contact and form an electrical connection between the circuits.

Obviously, the result is the same whether the wire moved is of circuit A or of circuit B, for in one case the entire spanner will be displaced, and in the other the spanner remains stationary while the .moved wire is brought into contact with the loop ll surrounding it.

It is also obvious that while Figure 1 shows all of the wires of the fence charged and insulated from the ground, it is possible through use of the spanner to have some of the Wires uncharged and grounded and still retain good protection. In that case the spanner would be mechanically and electrically connected to the uncharged wires to move therewith while the charged wires would be encircled by the loops on the spanner. As a result of this construction abnormal flexure of any uncharged wire as well as abnormal flexure of any charged wire would effect grounding of any charged wire to set off the alarm.

Although the spanner may be made just long enough to span the'wires of a given fence, it is preferable to manufacture it in commercial lengths to be wound on spools in the customary manner. To this end, the length of wire which is to form the relatively stiff spanner per se may be fed past a spot welding machine at which the short lengths or pieces of flexible wire 9 have one end portion spot welded to the stiff wire as at H3. The stiff wire with the lengths of flexible wire welded thereto at spaced intervals can then be wound on a spool for commercial handling.

From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art,

.fence; a permanent electrical connection between the conductor and one of the fence wires; insulated mechanical connections between the conductor and other fence wires whereby the spanner is held against displacement with respect to said first designated wire and said other wires and flexure of any one of said wires moves the spanner with relation to the remaining wires; and contact members carried by the conductor and'embracing but spaced from said remaining wires of the fence so that abnormal flexure of any wire of the fence effects electrical connection between the wire with which the conductor is permanently electrically connected and one of said remaining wires of the fence.

2. In an electrified fence having spaced wires forming two circuits: means for shorting said circuits of the fence in the'event of abnormal flexure of any wire thereof comprising, a conductor spanning all of the wires; a permanent electrical connection between the conductor and one wire of one circuit; a contactportion on the conductor embracing each wire of the other circuit but spaced therefrom; and means connecting the conductor with the remaining wires of the first designated circuit in a manner holding the con- 'ductor in a position at which its contact portions are spaced from the fence wiresembraced thereby as long as the fence wires are in their normal positions and whereby abnormal flexure of any wire results in engagement between a contact portion of the conductor and the wire it embraces.

3. In an electrified fence having spaced wires strung on posts but insulated therefrom with the wires arranged in two circuits and adjacent wires from different circuits: a spanner for establishing a short circuit between the circuits of the fence in the event of abnormal displacement of any wire thereof comprising, a' conductor electrically connected to one of the wires of one circuit; contact portions on the spanner embracing the wires of the other circuit but spaced therefrom as long as the wires are in their normal positions; and an insulated mechanical connection between the conductor and each remaining wire of the first designated circuit by which the conductor is held in a, predetermined position with respect to the fence wires as long as the wires remain in their normal positions and whereby abnormal flexure of any wire effects engagement between one contact portion of the conductor and the wire it embraces.

4. In an electrified fence: a spanner for short circuiting the fence in the event of abnormal flexure of any wire thereo-f comprising, a length of stiff wire spanning the wires of the fence; a plurality of relatively flexible wires electrically and mechanically secured to the stiff wire at spaced intervals, certain of said flexible wires being looped around adjacent fence wires without contacting the same; insulators on other fence wires; and loops formed by the adjacent flexible wires encircling the insulators to mechanically support the conductor from said other fence wires.

5. As an article of manufacture, a spanner for electric fences comprising: a relatively stiff conductor; and a plurality of relatively flexible conducting wires electrically and mechanically secured thereon at spaced intervals, each adapted to be looped around a fence wire.

6. As an article of manufacture, a spanner for electric fences comprising: a long length of relatively stifi wire; and a plurality of short lengths of relatively flexible wire electrically and mechanically secured to the stifi wire at spaced intervals with the securement of said flexible wires confined to one end portion of each so that the major portion of each flexible wire is free to be looped about a fence wire.

7. In an electrified fence having a plurality of spaced wires strung on spaced supports, at least one of the wires being part of one circuit and at least one other wire being part of another circuit: a spanner for electrically connecting said two wires in the event of abnormal flexure of any wire of the fence between its supports comprising, a conductor spanning all of the wires; an electrical and mechanical connection between one of said two wires and the conductor; contact means on the conductor embracing, but normally not touching the other one of said two wires and any other wire of the fence having the same potential; and mechanical connections between the conductor and any other fence wire of the same potential as the first designated one of said two wires.

8. In an electrified fence having spaced electrically charged wires mounted on spaced supports and normally insulated from each other: means for short circuiting said wires in the event of abnormal fiexure of either one of them between their supports comprising a conductor spanning the wires between their supports; a mechanical and electrical connection between the conductor and one of the wires; and a conducting loop carried by the conductor and embracing the other wire to contact the same in the event of abnormal fiexure of either of the wires.

SIDNEY A. MOORE. 

